Occluders are implants that are used for occluding passages or openings in circulatory systems, such as blood vessels or shunt connections, and are usually positioned and expanded via a sheath introduced into a vein. Occluders serve in particular for occluding openings in the heart or in another bodily channel in the human or animal body. By way of example, occluders serve to occlude a patent ductus arteriosus (PDA), an atrial septal defect (ASD) or a ventricular septal defect (VSD). Other applications in the human and animal body are possible.
The prior art has disclosed the most diverse types of embodiments for occluders. By way of example, occluders can be embodied as a helical spring or can be opened like an umbrella. Furthermore, they can occlude the passage from only one side or from both sides. These occluders can usually be brought into an elongate form so that by means of the catheter they can be brought to the passage that should be occluded. There the occluder is released and it assumes the expanded usage form thereof, either independently or in a guided fashion.
WO 2005/074813 discloses an occluder with two expansion units and two closure bodies, which in each case rest against one side of the passage. The occluder is illustrated in FIGS. 1 and 2. The expansion units are formed by wires 3, which are held in a first coupling part 1 with a first end and in a second coupling part 2 with a second end. The wires 3 are bent by the two coupling parts 1, 2 approaching one another and form two rosette-like flat structures. The closure bodies are circular membranes 4, 5, which are penetrated by the wires 3. These membranes 4, 5 are opened by the wires 3 when the coupling parts 1, 2 are brought together. The membranes occlude the body passage from both sides. In the expanded manifestation as per FIG. 2, the coupling parts 1, 2 can be inserted into one another, and so the occluder is fixed in the manifestation.
WO 2007/115117 discloses an occluder with expansion units resting against the body passage on both sides, wherein the distance between the expansion units can be matched to the depth of the passage.